High voltage circuit breaker

ABSTRACT

The invention proposes a high voltage circuit breaker, which contains a switching arrangement in a metal housing, which in the past included structural support for the switching arrangement in the housing. The present proposal does away with the structural support by including impedance elements into the housing which have sufficient rigidity so as to act as a mechanical support and thus obviate the use of other structural elements.

United States Patent 1191 Beier Apr. 17, 1973 [5 HIGH VOLTAGE CIRCUITBREAKER 3,075,060 1/1963 Strom ..200/148 D 3,160,727 12/1964 Colclaser,Jr. et al.. ....200/l44 AP [75] Inventor Helm Germany 3,446,928 5/1969Harper et al. ..200/144 AP [73] Assignee: Siemens Aktiengesellschaft,Munich,

Germany Primary ExaminerRobert S. Macon [22] Filed: Feb. 4Att0rney-Arthur Wilfond et a1.

[2]] Appl. No.: 223,637 [57] ABSTRACT The invention proposes a highvoltage circuit breaker, [30] Forelg Apphcauo Pnonty Data which containsa switching arrangement in a metal Feb. 17, 1971 Germany ..P 21 08 265.5housing, which in the P included Structural Support for the switchingarrangement in the housing. The [52] US. Cl. ..200/144 AP, 200/ 148 Dpresent proposal does away with the structural support [51] Int. Cl...HOlh 33/16 by including impedance elements into the housing [58] Fieldof Search ..200/148 R, 144 AP, which have sufficient rigidity so as toact as a 200/l48 D mechanical support and thus obviate the use of otherstructural elements. [56] References Cited 7 Claims, 1 Drawing FigureUNITED STATES PATENTS 3,052,783 9/1962 Buron ..200/144 AP BACKGROUND OFTHE INVENTION 1 Field of the Invention This invention relates generallyto a rotary meat slicing knife for severing a slice of meat from alarger piece upon one revolution thereof.

2. Description of the Prior Art Slices of meat, such as steaks, chops orslices of ham, have been commonly cut from a larger piece of meat, suchas a loin or whole ham, by a meat cutting band saw, appreciable operatortime being required for cutting a quantity of such slices. A productionmeat slicing machine has been introduced which automatically feeds alarge piece of meat to a rotating, eccentric knife blade which seversone piece of meat from the larger piece upon each revolution of theblade. The knife blade employed in that machine is generallycrescent-shaped with a convexly curved cutting edge, the blade beingmounted for eccentric rotation adjacent one of its ends and the cuttingedge having serrations formed therein.

SUMMARY OF THE INVENTION A rotary meat slicing knife comprising a bladehaving opposite sides and a convexly curved, uninterrupted, sharpenedcutting edge extending continuously between opposite extremities. Meansare provided for mounting the blade for eccentric rotation in a givendirection about an axis normal to the blade sides with the leading oneof the cutting edge extremities being more closely spaced from the axisof rotation than the trailing one of the extremities. One side of theblade has a plurality of circumferentially contiguous segments formedthereon adjacent said cutting edge and extending between the cuttingedge extremities. Each of the segments comprises a surface whichsmoothly tapers away from the cutting edge and which also smoothlytapers in thedirection of rotation toward the other side of the blade tothe adjacent segment thus forming a compound wedge configurationpointing toward the cutting edge and in the direction of rotation forseparating a slice of meat from a larger piece upon one revolution ofthe blade.

It is accordingly an object of the invention to provide an improvedrotary meat slicing knife.

The above-mentioned and other features and objects of this invention andthe manner of attaining them will become more apparent and the inventionitself will be best understood by reference to the following descriptionof an embodiment of the invention taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary view inperspective, partly broken away, illustrating a meat slicing machineincorporating the improved rotary meat slicing knife of the invention;

FIG. 2 is a side view of the rotary meat slicing knife of the invention;

FIG. 3 is a top view of the knife of FIG. 2;

FIG. 4 is a cross-sectional view taken generally along the line 4-4 ofFIG. 2;

FIG. 5 is a cross-sectional view taken generally along the line 5-5 ofFIG. 2;

FIG. 6 is an end view as viewed generally along the line 6-6 of FIG. 2;

FIG. 7 is a fragmentary cross-sectional view taken generally along theline 7-7 of FIG. 2;

FIG. 8.is a fragmentary view in perspective further illustrating thewedge segments of the knife of the previous figures; and

FIG. 9 is another side view of the knife of the inven- 0 tionillustrating its slicing action.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, thereis shown a portion of a meat slicing machine, generally indicated at 10,having a meat loading and feeding bin 12, a slice-receiving bin 14, andthe improved rotary meat slicing knife 16 of the invention mounted forrotation between bins l2 and 14 within'guard l8. Knife 16 is driven by asuitable motor (not shown) through gear box 20. Suitable meat feedingmechanism 22, which does not form a part of the present invention, isactuated by lead screw 24 driven by gear box 20, and incrementally feedsthe piece of meat in bin 12 forwardly under knife 16 in response to eachrevolution thereof thereby to slice off one slice of the desiredthickness.

Referring now to FIGS. 2 through 7 of the drawings, knife 16 comprisesgenerally crescent-shaped blade 26 having opposite ends 28, 30 andconvexly curved, uninterrupted, sharpened cutting edge 32 having itsopposite extremities 34, 36 terminating at blade ends 28, 30. In theillustrated and preferred embodiment, cutting edge 32 is accuratelycurved having the center of its radius of curvature located as shown at38 in FIG. 2.

Back-up plate 38 engages side 40 of blade 26, mounting hub 42 engagesback-up plate 38, and mounting hub 44 engages side 46 of blade 26, blade26, back-up plate 38 and mounting hubs 42, 44 being held in assembledrelation by suitable screws 48. Back-up plate 38 has beveled edges 39facing cutting edge 32. Sleeve 50 extends through openings in blade 26,backup plate 38 and mounting hubs 42, 44 and is secured thereto bysuitable screws, one of which is shown at 52. Knife 16 is adapted to bemounted on the output shaft (not shown) of gear box 20 by means ofsleeve 50 which has a keyway 54 therein for keying knife 16 to theoutput shaft. Cap 56 covers one end of sleeve 50 and is secured tomounting hub 42, as be welding.

It will now be seen that knife 16 is adapted to be mounted for eccentricrotation about axis 58 adjacent end 28 of blade 26. Knife 16 is rotatedby the motor and gear box 20 in the direction shown by arrow 60,extremity 34 of cutting edge 32 thus being the leading extremity andbeing more closely spaced from axis of rotation 58 than the trailingextremity 36.

In accordance with the invention, side 40 of blade 26 has a plurality ofcircumferentially' contiguous segments 60, 62 formed thereon adjacentcutting edge 32 and extending between extremities 34, 36. Each segment62 is formed by surface 64 which, as viewed in transverse cross-sectionas seen in FIGS. 4, 5 and 6, tapers smoothly away from cutting edge 32and, as viewed in longitudinal cross-section as shown in FIG. 7, alsotapers smoothly in the direction of rotation 60 toward side 46 of theblade to the'adjacent segment 62.

Side 46 of plate 26 is substantially flat and, by virtue of the taper ofsurface 64 in direction of rotation 60, each segment 62 is joined to theadjacent segment by a discrete trailing edge 66 which extends inwardlyfrom cutting edge 32 and is preferably slightly inclined in direction ofrotation 60, as best seen in FIG. 2. Tapered surface 64 of each segment62 thus forms a compound wedge configuration which points toward cuttingedge 32 and in the direction of rotation 60. Blade 26 may be formed ofany suitable metal and in a specific embodiment is formed of D-2 airhardened tool steel.

Referring now to FIG. 9 of the drawings, the relationship of knife 16 toloading and feeding bin 12 is shown as viewed generally in the directionshown by the arrow 9 in FIG. 1, guard 18 being eliminated. A piece ofmeat 68 having bone 70 therein, such as a beef loin from which steaksare to be sliced, is shown positioned in bin 12. With knife 16continuously rotating in direction 60, and with knife 16 generally inthe position shown in FIG. 1, feeding mechanism 22 pushes piece 68 ofmeat forwardly the requisite distance so that upon the next revolutionof knife 16, a slice of the desired thickness will be cut-off. In aspecific embodiment, a 1,750 r.p.m. motor is employed with gear box 20providing a to 1 speed reduction thus driving knife 16 at 175 r.p.m. soas to provide 175 slices per minute.

The position of cutting edge 32 immediately prior to beginning a slicingoperation is shown in dashed lines at 32-1, and intermediate positionsduring the slicing operation are shown in dashed lines at 32-2 and insolid lines in FIG. 9. Considering now point 72 on cutting edge 32, thepath of movement of point 72 about axis 58 is shown by arrow 74. Thepath of movement 74 of point 72 can be vectorially resolved intocomponent 76 normal to cutting edge 32 and component 78 tangent tocutting edge 32, it being observed that the compound wedge configurationformed by the tapered surface 64 of the respective segment 62 islikewise tapered or pointed in directions 76, 78. It will further beseen that the wedges formed by surfaces 64 of the segments 62progressing toward trailing extremity 36 are moving at progressivelyhigher linear rates of speed. Thus, the cumulative effect of the slicingaction of the flying" wedges formed by tapered surfaces 64 is smoothlyto separate the slice of meat from piece 68, wedges 64 and tapered edges39 of back-up plate 38 ejecting the resulting slice into receiving bin14.

The improved slicing knife 16 of the invention provides smoother, easierand faster cutting with less power than prior art machines.

While the flying wedge cutting edge configuration of the invention isparticularly applicable to rotary meat slicing knives, as describedabove, it is also applicable to other types of slicing knives.

While there have been described above the principles of this inventionin connection with specific ap paratus, it is to be clearly understoodthat this descripsaid blade for eccentric rotation in a iven directionabout an axis normal to said sides with e leading one of said cuttingedge extremities being more closely spaced from said axis than thetrailing one of said extremities, one side of said blade having aplurality of circumferentially contiguous segments formed thereonadjacent said cutting edge and extending between said extremities, eachof said segments comprising a surface which smoothly tapers away fromsaid cutting edge and which also smoothly tapers in said directiontoward the other side of said blade to the adjacent segment therebyforming a compound wedge configuration pointing toward said cutting andin said direction for separating a slice of meat from a larger pieceupon one rotation of said blade.

2. The knife of claim 1 wherein said segments respectively havesubstantially the same size and configuration.

3. The knife of claim 1 wherein said other side of said blade issubstantially flat.

4. The knife of claim -1 wherein said cutting edge is arcuate with thecenter of its radius of curvature spaced from said axis.

5. The knife of claim 1 wherein each of said segments is joined to theadjacent segment by a discrete trailing edge.

6. The knife of claim 1 wherein said blade is generally crescent-shapedand has opposite ends, said cutting edge extremities being respectivelyat said ends, said axis being adjacent one of said ends.

7. The knife of claim 6 wherein said segments have substantially thesame size and configuration, said other side of said blade beingsubstantially flat, said cutting edge being arcuate with the center ofits radius of curvature spaced from said axis, each of said segmentsbeing joined to the adjacent segment by a discrete trailing edge.

8. A slicing blade having opposite sides and an uninterrupted, sharpenedcutting edge extending continuously between opposite extremities, oneside of said blade having a plurality of contiguous segments formedthereon adjacent said cutting edge and extending between saidextremities, each of said segments comprising a surface which smoothlytapers away from said cutting edge and which also smoothly tapers towardone of said extremities and the other side of said blade to the adjacentsegment thereby forming a compound wedge configuration pointing towardsaid cutting edge and said one extremity.

UNITED STATES PA'IENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,72@'3,5o) Dat April 1.7, 1973 Inventor(s) Helmet Beier It is certifiedthat error appears in the aboveidentified patent and that said LettersPatent are hereby corrected as shown below:

Cancel columns 1 thr-u L1, of. the printed patent and substitute theattached columns 1 thru L Signed and sealed this 30th day of April 197R.

(SEAL) Attes EDWARD l-'i.FLETGIIER,JR. C MARSHALL DANE Attesting OfficerCommissioner of Patents FORM PO-IOSO (10-69) USCOMM'DC GOS'IS-Pfi ".5.GOVERNMENT PRINTING OFFICE: "C! 0Ji-334.

I '1 HIGH voLTAcE" CIRCUIT BREAKER The invention relates to a highvoltage circuit breaker with a switching arrangement disposed in a metalhousing and insulated therefrom. The arrangeand is similarly disposed inthe metal housing. As a rule, in such circuit breakers, the so-calledswitching chamber tube has been provided in the form of an insulatingmaterial tube, which encloses'both of the switching pieces, as well asthe sliding contact and provides for the mechanical support of theswitching l5 arrangement. In place of the switching chamber tube,insulating material rods are used, as known from the US. Pat. No.3,160,727, wherein a circuit breaker has been described, in which, inaddition to nozzle 2 exceed the weight of the stationary switch piecesand the stresses occurring during the coaction of the stationary withthe movable pieces. The stresses due to the inertia of the movableswitch pieces are completely balanced out due to the symmetricalarrangement, so that the impedances, used as supporting insulatingelements, may be of a size which is particularly advantageous.

For the purpose of a better explantion of the invention, an exemplifiedembodiment will be described in connection with the accompanying FIGURE.A heavy-duty switch breaker will be described here comprising a metalencapsulated high voltage circuit breaker arrangement withsulfahexafluoride as a quenching and insulating gas using a potential of220 or more kV.

The circuit breaker includes a grounded metal housing 1, which consistsof a cylindrical portion 2 having three tubular pipe sockets 3, 4 and 5.The

bodies for the guidance of a quenching gas stream. insulating materialrods are used which are at least provided on opposite sides of. thecircuit'breaker arrangement, whereby a mechanically stabilizedladder-formed structure is obtained.

It is an object of the invention to provide a further simplificatiorfofhigh voltag circuit breakers of the type described. The inventionconsists in that the impedance at high voltage potential provides theonly rigid mechanical connection between the stationary switching pieceand the sliding contact.

In accordance with the invention, the impedance whose function it is tofacilitate the disconnect or connect of the high potential circuitbreaker or to act as a control impedance for the control of the voltage3 distribution, particularly in circuit breakers with multipleinterruption, simultaneously functions also as a mechanical constructionelement. 'As a result, the usual switching chamber tube or correspondinginsulating rods may be dispensed with.

are disposed about the switching unit and slide contact, preferably in asymmetrical manner. The mechanical stresses on the individual elementsare thereby reduced, while the costs may not have to be significantlyhigher when, by using equal impedances for different circuit breakers,an advantageously greater number of pieces may be provided.

In a particularly advantageous embodiment of the invention for circuitbreakers with two switching arrangements connnected in series, theswitching arrangements are carried by a single support. This supportengages in the middle of the structure at the ends of the switchesfacing each other. The other ends, which face away from each other, towhich electrical connections have been made without imposing mechanicalstresses thereon, are connected mechanically to the support only throughthe impedances in parallel with the switches. In this arrangement, thecontrol impedances are free of all mechanical stresses, which from endsof the cylindrical portion 2 are closed by means of covers 6 and 7.

Two equal, electrically in series connected switch includes twostationary electrodes 13 and 15, .which are hollow and function as jetnozzles. During the connect position, the electrodes are connectedthrough a hollow movable switching pin 14. The circuit then comprisesthe electrode 13, which is to be considered as a stationary portion,over the switching pin 14 to the electrode 15, which, acting as asliding contact, conducts the current from the switching pin 14 to astationary metal housing 16, disposed in the center between the twoswitching arrangements 11 and 12. A hollow supporting insulator 20consisting of cast resin engages the metal housing 16. The insulator 20is rigidly. connected with the metal housing 16 at its high potentialend. The grounded end of the O insulator, extending into the socket 4,is rigidly semotion of an insulating material driving rod 24 in the'direction of the axis of the insulator 20 which is guided through themetal housing 16 as at 25. Two angle levers 26 and 27,:movable incounteraction, are thereby set into motion and are coupled with themovable switching pins 14 of the switching arrangements 11 and 12through rods 28. Therods 28 are further connected with a blast cylinder30 which, during disconnect, is pulled over a stationary blast piston31, whereby by means of sulfahexafluoride, which is subject tocompression thereby and which streams through the hollow switch pieces13 and 14, a quenching of the electric arc is effected.

Arounded metal cap'33 is secured to the end of the respective switchingarrangements 11 and 12, which are remote from the support 20, whereonthe stationary switch piece 13 is supported. This metal cap is connectedwith the metal housing 16 over the control condensers 35, which areconnected in parallel to the switching arrangements 11 and 12, and whichserve to provide an even distribution of the potential on both of theswitching arrangrnents. The control condensers, with the aid of castresin, are made such that tliey are not only self-supporting, but arealso capable of taking up mechanical stresses. Individually, they areconsidered as partial impedances, which are arranged in spatial symmetrywith respect to the switching arrangments 1 1 and 12. Although theracial caps 33 are connected through the plug contact connection 36 withthe conductor 37 of an inlet 38, the conical insulating bodies of whichare referred to at 39, the plug contact connection 36, however, is notcapable of transmitting mechanical stresses, since it is comprised oftwo sphere-like thickened conductor ends 41 and 42 which areelectrically connected through contact laminations 43. The contactlaminations are subject to the action of leaf springs 44 which aresupported at a cylindrical housing 45. Thus, a freely movable andelectrically well conducting connection is available so that mechanicalstresses are not capable of being transmitted from the switching unitsto their inlets. Thus, the only rigid mechanical connection between themetal cap 33, which supports the stationary switch piece 13 and thesliding contact 15, associated with the metal housing 16, is provided bythe impedances 35. It is thus possible to get along in this circuitbreaker, in accordance with the invention, with a few simple insulatingmaterial parts, which are protected against weathering by means of themetal housing 1.

Although the invention is illustrated and described herein as embodiedin high voltage circuit breaker, it is, nevertheless, not intended to belimited to the details shown, since various modifications and structuralchanges may be made therein without departing from the spirit of theinvention and within the scope and range of equivalents of the claims.

it is claimed:

1. A high voltage circuit breaker comprising a metal housing, at leastone switch arrangement disposed in said housing and electricallyinsulated therefrom; said switch arrangement including a stationaryswitch portion and a movable switch pin disposed for coaction therewith,and a stationary sliding contact for guiding said pin; an impedancedisposed in said housing for controlling the high voltage switchingforming the only rigid'mechanical connection between said stationaryswitch portion and said sliding contact.

2. The circuit breaker according to claim 1, wherein said impedancecomprises a condenser made of cast resin.

3. The circuit breaker according to claim 1, wherein said impedanceconsists of two or more partial impedances arranged for distributionabout said stationary switch portion and said slide contact.

4. The circuit breaker according to claim 3, wherein said distributionis symmetrical.

5. The circuit breaker according to claim 1, wherein there are includedtwo series connected switching arrangements each having two ends, oneend being adjacent to and facing and the other end being remote andfacing away from that of the other switch arrangement, means forsupporting said switching arrangements disposed adjacent said facingends, electrical connecting means connected to each of said remote ends,and means in said housing forming an inlet each for each of saidelectrical connecting means.

6. The circuit breaker according to claim 5, further including means formechanically linking said remote ends to said supporting meanscomprising solely said impedances disposed in parallel to said switchingarrangements.

7. The circuit breaker according to claim 6, wherein said electricalconnecting means, together with said inlet means, comprise plugcontacts, consisting of two coaxial conductors with sphere-like ends,and include a coupling contact piece encompassing said sphere-like ends.

1. A high voltage circuit breaker comprising a metal housing, at leastone switch arrangement disposed in said housing and electricallyinsulated therefrom; said switch arrangement including a stationaryswitch portion and a movable switch pin disposed for coaction therewith,and a stationary sliding contact for guiding said pin; an impedancedisposed in said housing for controlling the high voltage switchingforming the only rigid mechanical connection between said stationaryswitch portion and said sliding contact.
 2. The circuit breakeraccording to claim 1, wherein said impedance comprises a condenser madeof cast resin.
 3. The circuit breaker according to claim 1, wherein saidimpedance consists of two or more partial impedances arranged fordistribution about said stationary switch portion and said slidecontact.
 4. The circuit breaker according to claim 3, wherein saiddistribution is symmetrical.
 5. The circuit breaker according to claim1, wherein there are included two series connected switchingarrangements each having two ends, one end being adjacent to and facingand the other end being remote and facing away from that of the otherswitch arrangement, means for supporting said switching arrangementsdisposed adjacent said facing ends, electrical connecting meansconnected to each of said remote ends, and means in said housing formingan inlet each for each of said electrical connecting means.
 6. Thecircuit breaker according to claim 5, further including means formechanically linking said remote ends to said supporting meanscomprising solely said impedances disposed in parallel to said switchingarrangements.
 7. The circuit breaker according to claim 6, wherein saidelectrical connecting means, together with said inlet means, compriseplug contacts, consisting of two coaxial conductors with sphere-likeends, and include a coupling contact piece encompassing said sphere-likeends.